Thermostatic



Aug. 23, 192'?,

H. J. SAUVAGE THEnuosTAz-Ic APPLlANcE Filed Juiy 5. 1924 kjf i M un IV Patented Aug. 23, 1927.

Uh'lTED STATES PATENT OFFICE,

HERBERT J. SAUVAGE, OF CHCAGO, ILLTNOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE TRUSTEES OF ELECTRO THERMOSTATIC CONTROL COMPANY, OF CHICAGO,

ILLINOIS, A TRUST ESTATE.

THERMOSTATIC APPLIANGE;

Application filed July 5, 1924.

My invention concerns improvements in appliances sensitive to temperature changes and which are constructed to operate electrical or mechanical devices within certain llanges or temperature luctuations.

One object of the present invention is to provide a structure of this character oi the expansible and contractible bellows or accordion type or style which will operate with great accuracy and exactitude and within substantially narrower ranges of yteniperature change than similar appliances.

Another purpose of the invention is to supply a construction oli this orni which has no bearings directly or indirectly associated with the bellows device and hence the appliance includes no structure requiring oiling or 'which 'would be likely to collect dust and dirt by reason o the presence o a lubricant, such foulingl being detrimental to the etlective and elilcient operation of the structure.

A further aim of the invention resides in the production of a therinostatic appliance of this general character in which the two end Walls of the bellows are always maintained substantially true or in parallelism without the employment or bearings for guiding elements.

So 'lar as l am advised, it has been necessary heretofore to use some orm or style ot sliding bearing or itsequivalent to prevent the movable Aend wall oi the bellows trom becoming tilted or tipped out ot' its proper position.

lvly new device overcomes the employment ol such a bearing and at the same` time `the appliance is rendered more satisfactory and reliable in the performance of its functions.

To enable those skilled in this art to have a iull and complete understanding` ot the invention and its various structural and functional advantages, in the accompanying drawing forming a part olf this specitication, and throughout the views oi' which like reference characters relate to the same parts, I have illustrated a desirable and preterred embodiment of this invention.

in this drawing: i n

Figure 1 is an elevation of the thermo static appliance with the cover removed; and

Figure 2 is a vertical central cross-section of the device on line 2-2 of Figure 1, the

such depression.

Serial No. 724,278.

parts being viewed in the direction indicated by the arrows.

Referring to this drawing, it will be perceived that the improved and novel structure includes a supporting or back plate 10 of appropriate shape adapted to be fastened in any approved manner, not shown, on a wall.

Such member 1() has two, outstanding', horizontal, :dat lugs or ledges 11 and 12 projecting forwardly from its front tace.

The round or circular lower or end wall member 13 of the ybellows or accordion shaped unit lo, internally Supplied with a Vlluid quickly .and actively sensitive to temperature variations, such as ether, or amixture oi ether and alcohol, has athreaded boss 14 on its under face screwed into a threaded hole l5 in the projection 11, whereby such lower or bottom wall of the thermostatic device is liXedly maintained in a detinite plane, usually horizontal.

The top wall or round plate 17 or' the temperature-sensitive plaited or corrugated eX- tensible and reducible metal member 16 has a central depression 18, the face o'l which is a flat round surface. v

Internally this hollow, fluid-charged unit has a. longitudinally-disposed tube 19v`liXed tothe bottoni wall 13 with its upper end near the under face of the top wall 17, such hollow member acting as a stop or abutment to limit or restrict the descent of such top wall under the contracting action of the bellows.

A substantially-rectangular, upright yoke or frame 20 fits around or encloses the niember 1G and the under face or its top horizontal vwall has a cylindrical, latsur'faced boss received in the recess 18 and bearingl directly on the top wall of the bellows in t its top, this yoke has an upward extension 22 litted with an upper, flat, horizontal, bearing surface 23.

The bottom cross wall oi the yokey or frame has a pair 'of shallow, iupstanding,

.soaced luo's'with to) flat horizontal-surraces in the same plane or in register. These by bearing on the under lac'e ot the ledgell limitithe upward expansion ot the bellows and under those conditions they .maintain the top wall of the bellowsthrough the lug 21 from becoming` tilted or inclined out of its proper plane parallel to the wall i3 and the surfaces 24, 24.

' A coil contractile spring 25 has a loop or eye 26 at its upper end taking through a bevelled or doubly tapered aperture 2"? in the lower cross-wall ot' the yoke.

The other or opposite end of the spring encircles and is secured to a nut 28, the threaded aperture oi' which accommodates a vertical, screw-threaded shaft or rod 29, a reduced-diameter, cylindrical part 30 of which is revoluble in a bearing Ell in the lower ledge l2, the bottom protruding end portion of the section 3() being equipped with ya turning handle or disc 32 pinned thereon at 33.

ATo prevent the nut from turning with the rotation of the shaft, and hence causing Ythe movement or travel of the'nut longitudinally of the shaft, the nut has a lateral, bi-

urcated extension 345 straddling and cooperating with an upright,stationary rod 35 mounted in aligned holes in the two ledges.

At the top of the back or supporting plate a suitably-shaped sheet-metal cradle or saddle 36 is hinged or pivotedoP-center on an outstanding pin or shaft 37 carried by or mounted on the member lO and suoli sad le or cradle on its under surface has a lug 38 bearing on the face 23 of the yoke.

This cradle clamps around a hollow glass body 39 containing a small quantity oit inercury 40, which, under the rocking action of the hinged body makes and breaks electrical contact with a pair of terminals 4l and 42 located inside the glass shell and connected to wires 42 and 43 extending out backwards through the plate l() 'from which they are suitably insulated by proper bushings 44 and 45.

Owing to the llat, substantial bearine of the part 2l on the center of the upper Iace of the top wall of the bellows and the downward pull of the spring on the yoke along the aXis line of thebellows,vand because of the fact that the bottom wall of the bellows is xevdA and immovable, the force eX- erted by the spring holesy the bellows top wall in proper position under all circumstances precluding its becoming canted or tipped out of its correct horizontal relation.

This condition prevails throughout the range of movement of such top wall, but when the surfaces 24, 24 strike against the under face of ledge 1l, thus limiting the upward expansion of the bellows, the spring is no longer active and these cooperating surfaces then hold the wall in correct and proper position compensating under these conditions for the absence of the action of the spring.

The spring tension may, of course, be varied or adjusted by turning the screwshaft by means of its handle or handwheel 32.

Inasmuch as the glass body 39 and its mounting arehinged to one side ol: their center ot' gravity, they tend to rock down to the position shown in Figure l wherein the mercury closes the ele t ical circuit between the -pair ot enclosed terminals.

Such circuit will rcinain closed until the bellows expands under heat action and rocks the Mglass body and its mounting around the hinge causing the mercury to ilow down hill away from 4and breaking the circuit at such terminals. l y

As th-e top wall oi: the bellows descends under cooling` action or contraction, the electric-switch is permitted to swing down again into circuit-closing relation.

It is to be observed that the movable end wall of the bellows is always kept parallel to its bottom wallv and this is accomplished solely by the central pull ot the spring and without the employment ot any guiding bearings comprising relatively slidable elements necessitating lubrication and hence likely to become ifouledvwith adhering dust and dirt.

Itshould be noted that the single spring, by reason of its action on the yoke equipped with the member 2l bearing on the top wall ot the bellows throughout a substantial area keeps such top wall from tilting or becoming tipped in anyv direction whatsoever and this restricting influence is not limited to the plane of the yoke but is just as active in all other vertical planes. y

Whereas inthis application the new device has been shown and described in cooperative relation with an electric switch, it is to be iniderstoodthat it could just as readily coact with `some mechanical device designed to be operated upon changes of temperature.

Many minor mechanical changesI may be made in the device presented without departure from the substance and essence of the invention and without the sacriiice `ot any of its substantial beneiits and advantages or stated somewhat differently the invention'issusceptible of a variety of 'einbodiments allpfalling within the scope of the appended claims7 by which the invention is deined. y

Suitable stops, not fully shown in the drawing-,may be used if desired to limit the rocking movements of the mercury-equipped glassbody in bogth directions.

I claim: f y

l. In a tlierinostatic appliance ot the character described, the combination 'ot an cxpansible and contractible thermostatic bellows, a supporting ledge to which one end wall of said bellows is tixedly secured, said ledge having a surface parallel to the plane of said bellows end wall, a yoke around said bellows bearing on the outer face of the opposite end wall of said bellows,

lil

llO

a coil contractible spring secured to the yoke on the opposite side of said ledge :trom said bellows, and means to adjust the tension of said spring, said yoke under certain conditions being adapted to bear on said ledge surface and to maintain said movable bellows end wall parallel to said fixed bellows end wall.

2. In a thermostatic appliance of the character described, the combination of an expansible and contractible thermostatic bellows, a supporting ledge to which one end wall of said bellows is xedly secured, a yoke around said bellows bearing on the outer face of the opposite end Wall of said bellows, and a coil contractile spring secured to the yoke on the opposite side of said ledge :from the bellows and acting through the yoke to maintain the movable end wall of said bellows` substantially parallel to the fixed wall thereoll throughout the range of movement of said movable end wall.

3. In a thermostatic appliance of the character described, the combination of an expansible and contractible thermostatic bellows, a supporting ledge to which one end wall oi said bellows is fiXedly secured, a yoke around said bellows bearing on the outer face of the opposite movable end wall of said bellows, and a coil contractile spring secured to the yoke on the opposite side of said ledge from the bellows and on the aXis line of the latter, whereby said spring through the yoke tends to maintain said bellows end walls in substantial parallelism.

Il. In a thermostatic appliance of the character described, the combination of an eX- pansible and contractible thermostatie bellows, a supporting ledge to which one end wall of said bellows is fixedly secured, a yoke around said bellows bearing on the outer face or' the opposite movable end wall of said bellows, a coil contractile spring secured to the yoke on the opposite side of said ledge from `the bellows and substantially on the axis line of the latter, whereby said spring through the yoke maintains said bellows end walls in substantial parallelism, and means to adjust the tension of said spring.

5. In a thermostatic appliance of the character described, the combination of an expansible and contractible thermostatic bellows, means fiXedly holding one of the end walls of said bellows, a first substantiallyrictionless means constituting the sole means tending to maintain the opposite movable end wall of said bellows substantially parallel to said liXed end wall throughout the range of travel of such wall, and a separate second means to, keep said movable end wall in such parallelism when said rst means is inoperative to effect such parallelism.

6. In a thermostatic appliance of the character described, the combination of an ex- Vpansible and contractible thermostatic bellows, means to hold an end wall of said bellows in liXed position, and substantially- :trictionless means including an expanded spring tending to contract acting directly on the outer face of the opposite movable end wall of said bellows to prevent it from tilting throughout its range of travel.

In witness whereof I have hereunto set my hand.

HERBERT J. SAUVAGE. 

